AD1892JRRL Ver la hoja de datos (PDF) - Analog Devices

Número de pieza

componentes Descripción

Fabricante

AD1892JRRL

Integrated Digital Receiver/Rate Converter

Analog Devices 

AD1892

Decoded Channel Status Outputs (Continued)

Pin Name SOIC I/O Description

CC

19

O

In consumer mode, CC is the inverse Channel Status Bit 3, Byte 0 (C3, pre-emphasis). CC = 0

indicates that the audio material has been pre-emphasized; CC = 1 indicates that the audio material

has not been pre-emphasized.

In professional mode, CC is the most significant bit of the two bits that encodes the emphasis status

of the audio material.

Table I illustrates the professional mode emphasis encoding.

Table I. Professional Mode Emphasis Encoding

AD1892

Output

CC

CB

BYTE 0

Channel Status Bit

C2

C3

C4

Status

1

1

0

0

1

0

1

0

0

1

1

1

0

0

1

1

0

Emphasis not indicated. Receiver defaults to

no emphasis with manual override enabled.

0

None. Receiver manual override disabled.

0

50/15 µs. Receiver manual override disabled.

1

CCITT J. 17. Receiver manual override disabled.

CD

18 O

In consumer mode, CD indicates that the audio material is original over all category codes. The

state of this bit is affected by both the generation status “L” bit (Channel Status Bit 15, Byte 1) and

the category code (Channel Status Bits 8 through 14, Byte 1) since the definition of the L bit is re-

versed for three of the category codes (001XXXX, 0111XXX, and 100XXXX). CD = 0 indicates

that the audio material is original. CD = 1 indicates that the audio material is a copy (first genera-

tion or higher).

In professional mode, CD is the inverse of Channel Status Bit 9, Byte 1. CD provides some infor-

mation about channel mode. See below for additional details.

CE

17 O

In consumer mode, CE indicates the so-called “ignorant” category codes of “general” (0000 000)

and “A/D converter without copyright information” (0110 000). CE = 1 indicates that the audio

material is not encoded using an ignorant category code. CE = 0 indicates that the audio material is

encoded using an ignorant category code. This status output can be used in conjunction with the

CD output (Pin 18) to implement SCMS copy protection. See below for additional details.

In professional mode, CE indicates a Cyclic Redundancy Code (CRC) check error. CE = 0 indi-

cates that the calculated CRC value does not match the received CRC value. CE = 1 indicates that

the calculated CRC value does match the received CRC value. CE may be used to enable the dis-

play of the CA through CD states. If CE = 0, then CA through CD may be considered to be in

error, and their display should not be updated.

The Table II summarizes the function of the CA through CE pins, depending on the operating mode

(professional or consumer).

Table II. Decoded Channel Status Output Functions

CON/PRO 15 O

CSCLK 16 O

Pin Consumer

Professional

CA 0 = Audio, 1 = Nonaudio

0 = Audio, 1 = Nonaudio

CB 0 = Copy Permitted, 1 = Copy Inhibited Pre-emphasis Encoding

CC 0 = Pre-emphasis, 1 = No Pre-emphasis Pre-emphasis Encoding

CD 0 = Original, 1 = Copy

Inverse of Channel Status Bit 9

CE 0 = Ignorant Category, 1 = Not Ignorant 0 = C.S. CRC Error, 1 = No C.S. CRC Error

CON/PRO is defined as the inverse Channel Status bit 0, byte 0 (C0, pro/consumer). CON/PRO =

0 indicates professional mode. CON/PRO = 1 indicates consumer mode. The state of this pin inter-

nally determines the consumer/pro mode of the CA, CB, CC, CD and CE pins.

Channel Status Clock. Active HI (rising edge active). Outputs a pulse every 192 frames at the

start of the Channel Status block. Use the falling edge of this clock to latch the CA through CE

and CON/PRO output Channel Status signals. See Figure 38 for timing.

REV. 0

–5–

Share Link: